Actually, for maximum lifespan, LiPo batteries should be kept between 40% and 70% charge. But we want maximum time between charges, which is why we "abuse" them by "overcharging" them to more than 70%.

I'd like to see some evidence for this. It's true that LiPos should be kept stored at around those percentages, but so long as you're using them, then there's nothing wrong with fully charging them.

In fact, by charging them more frequently, you are damaging the cells. More frequent charging than is necessary can be harmful.